To: SI Bob who wrote (1881 ) 11/30/2007 12:02:49 AM From: Id_Jit Read Replies (1) | Respond to of 5691 Want to re-do the 700 mile trip driven the same way in the Camry for a MPG comparison? <g> In my mind, both cars are typically a fuel powered vehicle with electric power assist. Besides the electrical assist, a big difference between a hybrid vs. a conventionally powered similar vehicle is the engine’s size and horsepower. IMO hybrids are most efficient in accelerating and decelerating conditions such as in urban or suburban driving. Another efficient scenario could be hilly conditions; with a caveat. The caveat would be the maximum speed at which the electric motor could effectively assist. I’m not sure about this caveat however, as I don’t know the systems of either of the two cars. 700 miles is a long distance. Way too long for the potential energy of battery power alone. Even the potential energy in the fuel tank would require replenishment to complete the trip. I kinda guess that the big battery was close to the same state of charge when you got home as when you left. My point is that the trip was completed on the energy contained in the fuel tank NOT the battery. Yes, the electric drive likely helped acceleration at times; but it also likely hindered in the MPG department… Unless it was only recharged using wasted energy such as regenerative braking. If regenerative braking was not the only source for its recharge, then it was a parasitic on the fuel engine. (Battery charge and discharge efficiency is not 100%. There are other losses in these processes too.) Loosely from: en.wikipedia.org (2006 to present model) “1.3 L single overhead cam four-cylinder gas engine… This increases power to 93 hp @ 6000 rpm. …20 hp brushless, permanent magnet assist motor.” My antique ’90 Civic hatchback has a 1.5 L engine with 92 spec. HP. It is smaller and lighter than your Civic but not as aerodynamic nor as efficient. On a long weekend trip at similar speeds across prairie, hills, foothills, and into the mountains (including city driving) it will get around 38-39 MPG (US gallons), and that’s on 89 octane 5% ethanol gas. Your point about a Diesel engine is spot on, but don’t expect increased MPG’s on a long highway trip just because it is a hybrid -Diesel. Id